中文说明：OFDM它的初级形式被认为是一种数字调制技术，而不是一个多用户信道接入方法，由于它用于在使用OFDM符号中的一个序列中的一个通信信道传送一个比特流。 OFDM可以与其他形式的空间分集，例如天线阵列和MIMO信道进行组合 术语离散多音调制（DMT）表示分别调整所传输到的信道条件对每个副载波，通过所谓的比特加载的装置，基于OFDM的通信系统。
English Description：
OFDM in its primary form is considered as a digital modulation technique, and not a multi-user channel access method, since it is utilized for transferring one bit stream over one communication channel using one sequence of OFDM symbols. OFDM may be combined with other forms of space diversity, for example antenna arrays and MIMO channels The term discrete multitone modulation (DMT) denotes OFDM based communication systems that adapt the transmission to the channel conditions individually for each sub-carrier, by means of so-called bit-loading.